Filter-bed.



No. 647,453. Patented Apr. l0, I900. 1 c. c. SCAIFE & J. m. DAVIDSON. 1 FILTER BED.

1 (Application filed Jan. 22, 1900.)

(No Model.)

UNITED STATES PATENT OFFICE.

CHARLES C. SOAIFE AND JOHN M. DAVIDSON, OF ALLEGHENY, PENNSYL- VANIA, ASSIGNORS TO JAMES VERNER SCAIFE, OF SAME PLACE.

FILTER-ciao.

SPECIFICATION forming part of Letters Patent No. 647,453, dated Asst 10, 1906. Application filed January 22, 1900. Serial No. 2,375. (No model.)

Our invention relates to filters especially adapted for purifying water, has especial reference to filter-beds, and consists in certain I improvements in construction, which will be fully disclosed in the following specification and claims.

In the accompanying drawings, which form part of this specification, Figure 1 represents a side elevation of a filter, partly broken away to show the filter-bed and Fig. 2 represents some of the diiterent forms of the bodies in the filter-bed. V

In the practical use of filters containing beds of granular material the bed becomes packed by the pressure of the water passing through the filter and the particles of the bed adhere or become cemented together by the chemicals and impurities contained in the 0 Water, so that the bed frequently forms into a mass or lumps or strata, and when the current of Water is reversed to clean the filterbed it frequently occurs that the water will rise through the bed in separate streams or 3 5 courses and will leave a large part of the bed in an unpenetrated or undisturbed mass, or the water cuts its way through the bed in direct lines from the point of inlet to the point of outlet, thusagain leaving a large part of the bed that is not affected by the reverse current of the water and is consequently not cleaned. To overcome this serious difficulty, various devices have been employed, such as mechanical agitators to be operated by hand; 5 but these frequently become so solidly embedded in the packed filter-bed that they cannot be moved, and in some instances the filter-bed has had to be removed by cutting it out of the filter with a hammer and chisel or with a bar of metal. We have discovered by practical tests that, the placing of bodies of burnt fire-clay or burnt clay or vitreous material of irregular form in and interspersing them through the granular bed of sand or quartz and charcoal iii an altogether irregu- 5 5 lar manner and avoiding such form of the bodies and anyarrangement of them in the filter bed as will operate by the liquid passing through the filter-bed to pack said bodies and prevent the passage of liquid between them retards the adhesion or cementing of the bed in mass, lumps, or strata, as the sand will not readily adhere to the bodies, and also greatly facilitates the water in working its way through the filter-bed for cleaning it, and

that the bodies are tumbled about by the pressure of the reverse current of water so violently that they break up any crusted or lumped particles, and the bed and the bodies are thoroughly cleaned by attrition.

Reference being had to the drawings and the letters thereon, A indicates the body of the filter, which may be of any approved form and is providedwith the usual watersupply pipe B, three-way cock 0 for chang- 7 ing or reversing the current for cleaning the filter-bed, and the waste-pipe D, all of which may be of any approved form of construction.

E indicates the filter bed, composed of granular material asuch as sand, crushed 8o quartz,and charcoal-and through the bed are interspersed bodies I), irregular in form, and arranged inirregular form, so that they will notlie close together and form a compact body, preventing the passage of liquid between them in filtering, but will retard the adhesion of the particles and the forming of a mass, lumps, or strata by cementation produced by the coagulation of chemicals, lime, sulfur, iron, and

the slimy matter contained in the water and 6 break up any caked or lumped particles of the bed. The bodies 17 may be made in various irregular forms, as shown in Fig. 2, and are preferably made of burnt fire or other clay, pieces of broken'pottery-ware, or vitre- 5 ous material, and for some purposes they may be made of cast-iron; but the burnt fire or other clay in the several forms shown is preferred.

To clean the filter-bed, the cock 0 is turned and the current of the water reversed and directed through the bottom of the filterchamber, when the Water coming in contact with the bodies b is deflected and cuts its way through the entire filter-bed, the granules of Having thus fully .describedou r invention,

What We claim is- 1. A filter-bed composed of granular material and bodies of irregular form irregularly interspersed through the granular material,

to prevent packing of said bodies in filtering,

and to break up the filter-bed in cleaning the bed.

2. A filter-bed composed of granular mate rial and free bodies of irregular form irregularly interspersed through and commingled with the granular material, to prevent packing of said bodies in filtering, and to break up the filter-bed in cleaning the bed.

3. A filter-bed composed of granular material and free bodies of burnt clay or vitreous material irregular in form and irregularly interspersed through and commingled with the granular material, to prevent packing of said bodies in filtering and to break up the filterbed in cleaning the bed.

In testimony whereof we affix our signatures in presence of two witnesses.

CHARLES C. SOAIFE. JOHN M. DAVIDSON.

Witnesses:

CLARENCE A. YOUNG, HARRY S. OBERLIN. 

